Rain billing nightmare

At this point being angry is an understatement, I've been using rain 4G service since 2021 and had no problems until I change to the 101 router in 07/01/2025 when the purchase was made I was quoted a prorata amount of R423.39 which I paid and was debited again R111.61 on 25/01/2025 which means I do not owe rain for January... To my surprise today my services have been cut because I owe them R1500 mind you my payment date is set for 25th and should only be R625 for the service used in February. I have called so many times to get this sorted and everytime I'm being told in will be escalated to billing and they will get back to me and guess what no one ever gets back to me!!!!